Add packaging game files and bundling them into final Web app

Source/Editor/Cooker/Platform/Web/WebPlatformTools.cpp

@@ -5,12 +5,14 @@
 #include "WebPlatformTools.h"
 #include "Engine/Platform/File.h"
 #include "Engine/Platform/FileSystem.h"
+#include "Engine/Platform/CreateProcessSettings.h"
 #include "Engine/Platform/Web/WebPlatformSettings.h"
 #include "Engine/Core/Config/GameSettings.h"
 #include "Engine/Core/Config/BuildSettings.h"
 #include "Engine/Content/Content.h"
 #include "Engine/Content/JsonAsset.h"
 #include "Engine/Graphics/PixelFormatExtensions.h"
+#include "Editor/Cooker/GameCooker.h"
 
 IMPLEMENT_SETTINGS_GETTER(WebPlatformSettings, WebPlatform);
 
@@ -48,12 +50,107 @@ PixelFormat WebPlatformTools::GetTextureFormat(CookingData& data, TextureBase* t
 bool WebPlatformTools::IsNativeCodeFile(CookingData& data, const String& file)
 {
     String extension = FileSystem::GetExtension(file);
-    return extension.IsEmpty() || extension == TEXT("html") || extension == TEXT("js") || extension == TEXT("wams");
+    return extension.IsEmpty() || extension == TEXT("html") || extension == TEXT("js") || extension == TEXT("wasm");
+}
+
+void WebPlatformTools::OnBuildStarted(CookingData& data)
+{
+    // Adjust the cooking output folder for the data files so file_packager tool can build the and output final data inside the cooker output folder
+    data.DataOutputPath = data.CacheDirectory / TEXT("Files");
 }
 
 bool WebPlatformTools::OnPostProcess(CookingData& data)
 {
+    const auto gameSettings = GameSettings::Get();
+    const auto platformSettings = WebPlatformSettings::Get();
+    const auto platformDataPath = data.GetPlatformBinariesRoot();
+
+    // Get name of the output binary (JavaScript and WebAssembly files match)
+    String gameJs;
+    {
+        Array<String> files;
+        FileSystem::DirectoryGetFiles(files, data.OriginalOutputPath, TEXT("*"), DirectorySearchOption::TopDirectoryOnly);
+        for (String& file : files)
+        {
+            if (file.EndsWith(TEXT(".js")))
+            {
+                String outputWasm = String(StringUtils::GetPathWithoutExtension(file)) + TEXT(".wasm");
+                if (files.Contains(outputWasm))
+                {
+                    gameJs = file;
+                    break;
+                }
+            }
+        }
+    }
+    if (gameJs.IsEmpty())
+    {
+        data.Error(TEXT("Failed to find the main JavaScript for the output game"));
+        return true;
+    }
+
+    // Pack data files into a single file using Emscripten's file_packager tool
+    {
+        CreateProcessSettings procSettings;
+        String emscriptenSdk = TEXT("EMSDK");
+        Platform::GetEnvironmentVariable(emscriptenSdk, emscriptenSdk);
+        procSettings.FileName = emscriptenSdk / TEXT("upstream/emscripten/tools/file_packager");
+#if PLATFORM_WIN32
+        procSettings.FileName += TEXT(".bat");
+#endif
+        procSettings.Arguments = String::Format(TEXT("files.data --preload \"{}@/\" --lz4 --js-output=files.js"), data.DataOutputPath);
+        procSettings.WorkingDirectory = data.OriginalOutputPath;
+        const int32 result = Platform::CreateProcess(procSettings);
+        if (result != 0)
+        {
+            if (!FileSystem::FileExists(procSettings.FileName))
+                data.Error(TEXT("Missing file_packager.bat. Ensure Emscripten SDK installation is valid and 'EMSDK' environment variable points to it."));
+            data.Error(String::Format(TEXT("Failed to package project files (result code: {0}). See log for more info."), result));
+            return true;
+        }
+    }
+
     // TODO: customizable HTML templates
+
+    // Insert packaged file system with game data
+    {
+        String gameJsText;
+        if (File::ReadAllText(gameJs, gameJsText))
+        {
+            data.Error(String::Format(TEXT("Failed to load file '{}'"), gameJs));
+            return true;
+        }
+        const String filesIncludeBegin = TEXT("// include: files.js");
+        const String filesIncludeEnd = TEXT("// end include: files.js");
+        if (!gameJsText.Contains(filesIncludeBegin))
+        {
+            // Insert generated files.js into the main game file after the minimum_runtime_check.js include
+            String fileJsText;
+            String fileJs = data.OriginalOutputPath / TEXT("files.js");
+            if (File::ReadAllText(fileJs, fileJsText))
+            {
+                data.Error(String::Format(TEXT("Failed to load file '{}'"), fileJs));
+                return true;
+            }
+            const String insertPrefixLocation = TEXT("// end include: minimum_runtime_check.js");
+            int32 location = gameJsText.Find(insertPrefixLocation);
+            CHECK_RETURN(location != -1, true);
+            location += insertPrefixLocation.Length() + 1;
+            fileJsText = filesIncludeBegin + TEXT("\n") + fileJsText + TEXT("\n") + filesIncludeEnd + TEXT("\n");
+            gameJsText.Insert(location, fileJsText);
+            File::WriteAllText(gameJs, gameJsText, Encoding::UTF8);
+        }
+    }
+
+    const auto buildSettings = BuildSettings::Get();
+    if (buildSettings->SkipPackaging)
+        return false;
+    GameCooker::PackageFiles();
+
+    // TODO: minify/compress output JS files (in Release builds)
+
+    LOG(Info, "Output website size: {0} MB", FileSystem::GetDirectorySize(data.OriginalOutputPath) / 1024 / 1024);
+
     return false;
 }